Air feed blower, especially for a vehicle heater

ABSTRACT

An air feed blower, especially for a vehicle heater, includes an electrically driven blower drive motor ( 14 ) as well as an air feed wheel ( 16 ) that can be driven by the blower drive motor ( 14 ), wherein the blower drive motor ( 14 ) is electrically contacted with the use of spring contacts ( 34 ).

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2011 075 476.8 filed May 9, 2011, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains to an air feed blower, especially for a vehicle heater, comprising an electrically driven blower drive motor as well as an air feed wheel that can be driven by the blower drive motor.

BACKGROUND OF THE INVENTION

Such air feed blowers, generally also called side duct blowers, are frequently used in vehicle heaters in order to feed to a combustion chamber combustion air, which forms a combustible air-fuel mixture with a fuel evaporated towards the combustion chamber, wherein the thermal energy made available during the combustion of this mixture is transferred, for example, at a heat exchanger to air being fed into the interior space of a space for heating this interior space.

Such air feed blowers used in vehicle heaters are subject to considerable temperature fluctuations due to their operation, especially at low outside temperatures. These may adversely affect especially the electric contacting, which is embodied, in general, by soldered or plug-type connections, so that no reliable contacting can be guaranteed as a result. Vibrations occurring during the operation of the vehicle heater or vehicle may likewise have an adverse effect on the electrical contacting of the blower drive motor.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an air feed blower, which has a more reliable electric contacting of the blower drive motor compared to conventional air feed blowers.

This object is accomplished according to the present invention by an air feed blower, especially for a vehicle heater, comprising an electrically driven blower drive motor as well as an air feed wheel, which can be driven by the blower drive motor, wherein said blower drive motor is contacted electrically with the use of spring contacts.

The use of spring contacts makes it possible, on the one hand, to effectively compensate the stresses, which are due to temperature fluctuations and act on the electric contacts, by the spring force exerted by the spring contacts, and, on the other hand, to effectively absorb the vibrations occurring during the operation of the blower drive motor. The known drawbacks of the conventional contacting can thus be avoided, as a result of which more reliable operation of an air feed blower is, on the whole, ensured.

The design of the air feed blower may be such that an air feed duct, which extends in a ring-shaped pattern about an axis of rotation and is open on an axial side covered by the air feed wheel with an inlet area and with an outlet area separated by an interrupter area from the inlet area, is provided in a blower housing connected to the blower drive motor, wherein an opening, through which passes a drive shaft of the blower drive motor, which said shaft is connected to the air feed wheel for joint rotation, is provided in the blower housing.

Provisions may be made in a preferred embodiment for insert pins to be received by the spring contacts to be provided in association with the spring contacts for the electric contacting.

The spring contacts may be designed in this case, for example, as leaf springs, which are in contact with the insert pins over a large area in the contacted state in which the insert pins are received, as a result of which reliable electric contact is established, on the one hand, and the mechanical fastening means that are otherwise necessary in case of the use of, for example, spring contact pins, are eliminated, on the other hand. Even though a plurality of electrically conductive materials can be used, in principle, for spring contacts designed for use with insert pins, which spring contacts are designed, for example, as leaf springs, the use of leaf springs and insert pins made of metal is advantageous especially in respect to high mechanical stability.

The design may, furthermore, be such that a control device is provided in association with the blower drive motor. The use of a control device makes it possible to coordinate the operation of the blower drive motor with the operation of other system areas, for example, the combustion chamber area, whose temperature is, in general, an essential parameter for the operation or for the actuation of the air feed blower.

Provisions may be made in a preferred embodiment for the control device to be arranged in the area of the blower drive motor. Such a measure makes possible a compact design of an air feed blower. It is now possible, for example, to consider accommodating the control device and blower drive motor in a common housing or providing fastening means, which permit the corresponding housing parts of the control device and of the blower drive motor to be assembled into a single housing in a simple manner. Moreover, no connection lines between the control device and blower drive motor, which are long in relation to the dimensions of the air feed blower, are needed in such a design, so that corresponding means for staying or fastening the connection lines can be eliminated, as a result of which the design is, on the whole, simplified.

To make it possible to do away with connection lines between the control device and blower drive motor altogether, the design may be such that fastening means comprising the spring contacts are provided in the area of the blower drive motor to arrange the control device. Furthermore, provisions may now be made for the control device to be fastened to the blower drive motor with the use of the insert pins received in the spring contacts.

The spring contacts may now be formed, for example, from two leaf springs, which have a distance from each other that is shorter than the thickness of the insert pins. By inserting the insert pins into the spring contacts, the two leaf springs are pushed apart, so that a mechanically stable, frictionally engaged connection develops between the insert pin and spring contact based on the now acting restoring force of the leaf springs.

There is, in principle, no restriction regarding the arrangement of the insert pins and spring contacts at the blower drive motor and at the control device. For example, a mechanical connection can thus be established between the control device and blower drive motor by arranging at the control device and at the blower drive motor an insert pin and a spring contact each at equal distances in corresponding positions for a certain arrangement of the control device relative to the blower drive motor. However, since it is, in principle, simpler to arrange the insert pins instead of the spring contacts at the control device, for example, by soldering into a control printed circuit board, a design in which the spring contacts are arranged at the blower drive motor and the insert pins at the control device is preferred.

There are, in principle, very many possibilities for the exact arrangement of the insert pins and spring contacts. However, it is advantageous concerning simple mounting of the control device on the blower drive motor if the control device can be fastened to the blower drive motor by a motion that is essentially at right angles or in parallel relative to the axis of rotation.

The present invention also pertains to a vehicle heater comprising an air feed blower according to the present invention.

The present invention will be explained in more detail below with reference to the two attached drawings. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of an air feed blower according to the present invention;

FIG. 2 is a view corresponding to FIG. 1 of an air feed blower of an alternative design;

FIG. 3 is a cross-sectional view according to line III-III in FIG. 1; and

FIG. 4 is a view corresponding to FIG. 3 of an air feed blower with a control device separated from the blower drive motor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in particular, FIG. 1 shows an air feed blower generally designated by 10. The air feed blower generally 10 comprises an electrically driven blower drive motor 14 having a drive shaft 12 extending along an axis of rotation A, as well as an air feed wheel 16, which is connected in its hub area 18 to drive shaft 12 for joint rotation about axis of rotation A. The blower drive motor 14 has a housing comprising a circumferential wall 14 a as well as a front side wall 14 b.

An air feed duct 22, which extends essentially in a ring-shaped pattern about the axis of rotation A and which is open towards an axial side facing the air feed wheel 16, is formed in a blower housing 20 connected to blower drive motor 14. Air feed wheel 16 has a ring-like recess 17, which corresponds to and is located opposite the air feed duct 22 and in which a plurality of feed blades following each other in the circumferential direction are arranged. An inlet area leading to air feed duct 22, an outlet area leading away from air feed duct 22, as well as an interruption area separating these areas are not shown in FIG. 1. Blower housing 20 has, furthermore, an opening 24, through the drive shaft 12 passes.

The air feed blower 10 shown in FIG. 1, which is generally called side duct blower, is frequently used in vehicle heaters in order to feed combustion air, which forms a combustible air-fuel mixture with a fuel evaporated towards the combustion chamber, to a combustion chamber. The thermal energy generated during the combustion of this mixture is transferred, for example, at a heat exchanger, to air being delivered into an interior space of a vehicle, for example, by means of a second air feed wheel, which is arranged at the end of the drive shaft 12 located axially opposite the air feed wheel 16 but is not shown in FIG. 1.

To control the operation of the blower drive motor 14 as well as also for coordination with the operation of other system areas, a control device 26 is provided in this exemplary embodiment, which comprises essentially a housing 28, a control printed circuit board 30 as well as two insert pins 32 arranged at the control printed circuit board 30. As is apparent from the cross-sectional view in FIG. 3, the insert pins 32 are arranged in a plane extending at right angles to the axis of rotation A in the embodiment shown in FIG. 1.

To fasten the control device 26 to the combustion chamber 14, end sections of the insert pins 32 are received in spring contacts 34, which are accessible, as is apparent from FIGS. 1, 3 and 4, via the circumferential wall 14 a. The spring contacts 34 comprise in this exemplary embodiment two leaf springs 36, which are in contact with the insert pins 32 in the state in which control device 26 is mounted on the blower drive motor 14. Even though a plurality of electrically conductive materials can be used, in principle, for the insert pins 32 and the leaf springs 36, the use of leaf springs 36 and insert pins 32 made of metal is preferred especially in respect to a high mechanical stability.

FIG. 4 shows a state in which control device 26 is not mounted on the blower drive motor 14. As is apparent from FIG. 4, the shortest distance p between the leaf springs is markedly shorter than the thickness q of the insert pins 32. As a result of this construction, the leaf springs 36 are pushed apart from one another when the insert pins 32 are inserted into the respective spring contacts 34. As a result, a mechanically stable contact is established due to the restoring force resulting therefrom. Reliable electric contact is guaranteed in this manner between the control device 26 and the blower drive motor 14 regardless of stresses caused by thermal effects or vibrations occurring during the operation.

The arrangement of the insert pins 32 as well as of the corresponding spring contacts 34 in a plane extending at right angles to the drive shaft, as in the embodiment shown in FIGS. 1, 3 and 4, is not essential. An arrangement in a plane extending in parallel to the axis of rotation A or any other desired arrangement of the corresponding insert pin-spring contact pairs is likewise conceivable, without going beyond the idea of the present invention.

Another embodiment of an air feed blower according to the present invention will be described below on the basis of FIG. 2.

Components that are identical or functionally identical to those in FIGS. 1, 3 and 4 are designated by the same reference numbers but increased by the number 100. The embodiment shown in FIG. 2 is described only insofar as it differs from the first embodiment according to FIGS. 1, 3 and 4.

The electric contacting of a blower drive motor 114 is likewise performed with the use of spring contacts 134 comprising leaf springs 136 as well as insert pins 132 received in same in the air feed blower 110 shown in FIG. 2. The insert pins 132 are likewise arranged at a control printed circuit board 130 of a control device 126. However, contrary to the first exemplary embodiment, the insert pins 132 are of an angulated shape, so that in a positioning of the control device 126 corresponding to the first exemplary embodiment relative to the blower drive motor 114, they are received in spring contacts 134 that are accessible via a front side wall 114 b of the housing of blower drive motor 114.

The two embodiments in FIGS. 1 and 2 thus differ essentially only in terms of the fastening of the control device to the blower drive motor. While the control device 26 according to the first embodiment can be fastened to the blower drive motor 14 by a motion essentially at right angles relative to the axis of rotation A by inserting the insert pins 32 into the spring contacts 34, the control device 126 according to the second exemplary embodiment can be fastened to the blower drive motor 114 by an essentially parallel motion relative to the axis of rotation A by inserting the insert pins 132 into spring contacts 134.

The fastening of the control device 26, 126 being described here by means of the insert pins 32, 132 received in the spring contacts 34, 134 represents a very simple possibility of fastening. However, it shall not, in principle, be ruled out hereby that additional fastening means, for example, ones comprising screw connections may be provided, especially if an especially stable fastening of the control device is desirable.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. 

1. An air feed blower comprising an electrically driven blower drive motor; an air feed wheel which can be driven by said blower drive motor; and spring contacts, wherein said blower drive motor is electrically contacted via said spring contacts.
 2. An air feed blower in accordance with claim 1, further comprising: a blower housing connected to the blower drive motor, said blower housing having an air feed duct extending in a ring-shaped pattern about an axis of rotation, said air feed duct being open on an axial side covered by said air feed wheel and having an inlet area and an outlet area separated from said inlet area by an interruptor area, said blower housing having an opening through which passes a drive shaft of said blower drive motor connected to the air feed wheel for joint rotation.
 3. An air feed blower in accordance with claim 1, further comprising insert pins received by said spring contacts, said insert pins being associated with said spring contacts for electric contact therewith.
 4. An air feed blower in accordance with claim 1, further comprising a control device associated with said blower drive motor.
 5. An air feed blower in accordance with claim 4, wherein said control device is arranged in an area of said blower drive motor.
 6. An air feed blower in accordance with claim 5, wherein fastening means comprising said spring contacts are provided for arranging said control device in an area of said blower drive motor.
 7. An air feed blower in accordance with claim 6, further comprising insert pins received by said spring contacts, said insert pins being associated with said spring contacts for electric contact therewith wherein said control device is fastened to said blower drive motor with the use of said insert pins received in said spring contacts.
 8. An air feed blower in accordance with claim 3, further comprising a control device associated with said blower drive motor wherein said control device is fastened to said blower drive motor with the use of said insert pins received in said spring contacts.
 9. An air feed blower in accordance with claim 8, wherein said spring contacts are arranged at said blower drive motor and said insert pins are arranged at said control device.
 10. An air feed blower in accordance with claim 7, wherein said control device is fastened to said blower drive motor by a motion that is essentially at right angles or in parallel relative to the axis of rotation.
 11. A vehicle heater comprising: an air feed blower comprising an electrically driven blower drive motor, an air feed wheel which can be driven by said blower drive motor and spring contacts, wherein said blower drive motor is electrically contacted via said spring contacts.
 12. A vehicle heater in accordance with claim 11, further comprising: a blower housing connected to the blower drive motor, said blower housing having an air feed duct extending in a ring-shaped pattern about an axis of rotation, said air feed duct being open on an axial side covered by said air feed wheel and having an inlet area and an outlet area separated from said inlet area by an interruptor area, said blower housing having an opening through which passes a drive shaft of said blower drive motor connected to the air feed wheel for joint rotation.
 13. A vehicle heater in accordance with claim 11, further comprising insert pins received by said spring contacts, said insert pins being associated with said spring contacts for electric contact therewith.
 14. A vehicle heater in accordance with claim 11, further comprising a control device associated with said blower drive motor.
 15. A vehicle heater in accordance with claim 14, wherein said control device is arranged in an area of said blower drive motor.
 16. A vehicle heater in accordance with claim 15, wherein fastening means comprising said spring contacts are provided for arranging said control device in an area of said blower drive motor.
 17. A vehicle heater in accordance with claim 16, further comprising insert pins received by said spring contacts, said insert pins being associated with said spring contacts for electric contact therewith wherein said control device is fastened to said blower drive motor with the use of said insert pins received in said spring contacts.
 18. A vehicle heater in accordance with claim 13, further comprising a control device associated with said blower drive motor wherein said control device is fastened to said blower drive motor with the use of said insert pins received in said spring contacts.
 19. A vehicle heater in accordance with claim 18, wherein said spring contacts are arranged at said blower drive motor and said insert pins are arranged at said control device.
 20. A vehicle heater in accordance with claim 17, wherein said control device is fastened to said blower drive motor by a motion that is essentially at right angles or in parallel relative to the axis of rotation. 